base::mac::IsOSSierra() -> base::mac::IsOS10_12(), etc.

third_party/WebKit/Source/platform/fonts/mac/FontFamilyMatcherMac.mm

  /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 120 matching lines @@
 NSFont* MatchNSFontFamily(NSString* desiredFamily, NSFontTraitMask desiredTraits, FontWeight desiredWeight, float size)
 {
     if ([desiredFamily isEqualToString:@"BlinkMacSystemFont"]) {
         // On OSX 10.9, the default system font depends on the SDK version. When
         // compiled against the OSX 10.10 SDK, the font is .LucidaGrandeUI. When
         // compiled against the OSX 10.6 SDK, the font is Lucida Grande. Layout
         // tests don't support different expectations based on the SDK version,
         // so force layout tests to use "Lucida Grande". Once the 10.10 SDK
         // switch is made, this should be changed to return .LucidaGrandeUI and
         // the Layout Expectations should be updated. http://crbug.com/515836.
-        if (LayoutTestSupport::isRunningLayoutTest() && IsOSMavericks()) {
+        if (LayoutTestSupport::isRunningLayoutTest() && IsOS10_9()) {
             if (desiredWeight >= blink::FontWeightBold)
                 return [NSFont fontWithName:@"Lucida Grande Bold" size:size];
             else
                 return [NSFont fontWithName:@"Lucida Grande" size:size];
         }
 
         NSFont* font = nil;
-        if (IsOSMavericks()) {
+        if (IsOS10_9()) {
             // On older OSX versions, only bold and regular are available.
             if (desiredWeight >= blink::FontWeightBold)
                 font = [NSFont boldSystemFontOfSize:size];
             else
                 font = [NSFont systemFontOfSize:size];
         }
         else {
             // On OSX 10.10+, the default system font has more weights.
             font = [NSFont systemFontOfSize:size weight:toYosemiteFontWeight(desiredWeight)];
         }
@@ skipping 124 matching lines @@
         6, // FontWeight500
         8, // FontWeight600
         9, // FontWeight700
         10, // FontWeight800
         12, // FontWeight900
     };
     return appKitFontWeights[fontWeight];
 }
 
 } // namespace blink